Waste-derived biocatalysts for pesticide degradation

• Published in: Journal of hazardous materials Vol. 427; p. 127885
• Main Authors: Ferreira, José G.L., Takarada, Willian H., Orth, Elisa S.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 05.04.2022
• Subjects: Agriculture; Catalysis; Cellulose; Dephosphorylation reaction; Hydroxamic acid nucleophilic attack; Hydroxyl TEMPO-oxidation; Oryza; Pesticides; Pesticides degradation; Rice husk functionalization; Rice husk functionalization; Hydroxamic acid nucleophilic attack; Dephosphorylation reaction; Hydroxyl TEMPO-oxidation; Pesticides degradation
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2021.127885

A green approach to produce a cellulose-derived biocatalyst containing hydroxamic acids targeted for the neutralization of toxic organophosphates is shown. The cellulose source, rice husk, is among the largest agricultural waste worldwide and can be strategically functionalized, broadening its sustainable application. Herein, rice husk was oxidized in different degrees, leading to carboxylic acid-based colloidal and solid samples. These were functionalized with hydroxamic acids via amide bonds and fully characterized. The hydroxamic acid derived biocatalysts were evaluated in the cleavage of toxic organophosphates, including the pesticide Paraoxon. Catalytic increments reached up to 107-fold compared to non-catalyzed reactions. Most impressively, the materials showed P atom-selectivity and recyclability features. This guarantees only one reaction pathway that leads to less toxic products, hereby, detoxifies. Overall, highly sustainable catalysts are presented, that benefits from waste source, its green functionalization and is successfully employed for the promotion of chemical security of threatening organophosphates. To the best of our knowledge, this is the first report of a hydroxamate-derived rice husk (selectively modified at the C6 of cellulose) and its application in organophosphates reaction. [Display omitted] •Rice husk functionalized with hydroxamic acid as biocatalysts.•Sustainable approach for organophosphate neutralization.•Homogeneous and heterogenous catalysts derived from rice husk.•The real pesticide Paraoxon was efficiently degraded.